1. Field of the Invention
This invention relates to a motor drive mechanism for driving a camera having an automatic exposure control circuit.
2. Description of the Prior Art
A motor drive mechanism of the class described has been known wherein the mechanism comprises a trigger button to be depressed for driving the motor, and a switch to be closed during the depression of the button for supplying the power to the automatic exposure control circuit. However, the switch device has the following defects. During the exposure of a film especially in case of a long exposure time, it sometimes happens that a photographer would erroneously release the trigger button so that the supply of power to the automatic exposure circuit is discontinued resulting in an improper exposure. For example, in case of the type of camera in which the automatic exposure circuit controls the shutter and the trailing curtain is locked by an electromagnet, if the power supply to the exposure control circuit is interrupted before a required exposure time lapses, the electromagnet is deenergized so that the trailing curtain is released and the shutter is wholly closed thus prematurely interrupting the exposure.